I like Daz|Studio because of its ease of use.  It is easy to find objects to work with and to render with.  It's a poor man's poser, and a good place to start with 3D.  Although, with the new 3DBridge feature, it's easy to work in Photoshop.

A few merchants here do say that their stuff does work in Daz|Studio.  one of them I do use extensively in my renders.  Pretty3D being that one.